As generally known in the art, conventional technologies for downloading media from a server and playing them by user equipment are divided into two types: the entire media are downloaded and then played by the user equipment, or the media are streamed (i.e. packets of media are downloaded and played successively).
The streaming type lessens the communication burden on the user equipment or reduces the necessary storage capacity, and is widely employed.
As Internet technology has been recently developed and widely spread, various types of multimedia information are shared through the Internet more extensively than ever. As used herein, streaming refers to a type of data transfer, according to which a large amount of data is divided into packets of a predetermined size and transmitted from the server to the user s computer. Multimedia files (e.g. sounds, images) have a file size larger than that of text files, and it takes a long time to receive an entire multimedia file. According to the conventional download method, an entire file is transmitted and then watched. In contrast, according to the streaming method, a part of the entire file is transmitted and watched instantly, and the remaining part is continuously transmitted while the preceding part is being watched. The streaming method reduces the time to be spent until the file is ready to be watched, and is widely employed for Internet broadcasting, which provides a large amount of video and audio information.
Typical streaming methods include Real Media of RealNetworks and Windows Media Technology of Microsoft Corporation. In order to watch a streaming file on the web, the user needs to have a corresponding program, such as Real Player or Windows Media Player, installed on the computer. Real Media uses RM (*.rm) as a streaming file type and RAM (*.ram) as a metafile. Windows Media uses WMA (*.wma), WMV (*.wmv) and ASF (*.asf), as well as ASX (*.asx) as a metafile.
However, the conventional streaming methods have a problem in that they cannot substantially reduce the communication burden on the user equipment, and that the communication channel is occupied continuously.